Hydraulic booster

ABSTRACT

The disclosure hereof is of an hydraulic power amplifier or intensifier which includes a drive unit and a driven unit formed of large and small piston elements respectively, interconnected so as to be simultaneously operable, pressure applied to the larger of the units being calculated to in turn produce at the output end of the driven unit large pressures for operating various types of devices such as those used in utility construction and maintenance including cutters, swagers and the like, the disclosure providing a portable unit incorporating various controls which are desirable in the elements under consideration, and particularly making provision for pre-charging the system which produces the high pressure and applies the same to the operating tools. Control of the intensifier is effected by hand manipulation remotely arranged and connected so as to avail of low pressure for activating higher pressure elements or instrumentalities, the pre-charging arrangement serving to maintain the system at full pressure without air pockets and likewise acting to grip or hold parts initially prior to ultimate manipulation by the pressures supplied.

[ 1 July 31, 1973 HYDRAULIC BOOSTER [75] Inventor: Joseph C. Castleberry, Birmingham,

Ala.

[73] Assignee: Altec Manufacturing Company, Inc., Birmingham, Ala.

22 Filed: Feb. 5, 1971 21 Appl. No.: 112,955

52 U.S. c1 ..60/563 51 int. Cl. FlSb 7/00 58 Field of Search 60/54.5 HA, 54.6 HA,

60/54.5 H, 54.6 H, 54.5 A, 54.6 A, 54.5 P, 54.6 R; 91/461; 417/225 [56] References Cited UNITED STATES PATENTS 2,972,867 2/1961 Klingler 60/546 R 2,282,333 5/1942 Masteller 60/546 R 3,601,987 8/1971 Chermensky et al. 60/54.6 HA 2,279,364 4/1940 Canbury 417/225 1,787,328 12/1930 Schottler.. 91/461 2,598,907 6/1952 Griffin 91/461 3,340,897 9/l967' Nevalis 91/461 2,940,012 9/1959 Hazen 91/461 2,948,262 8/1960 Gratzmuller. 91/461 2,864,313 12/1958 Dawson 417/225 3,541,792 11/1970 Ellis 60/54.6 A 1,888,990 1l/1932 Kurath 60/545 HA 2,075,235 3/1937 Sciaky... 60/54.5 H 3,500,641 3/1970 Meckings 60/545 A FOREIGN PATENTS OR APPLICATIONS 128,027 1/1948 Australia 60/54.5 l-lA 922,787 1/1946 France 60/545 HA Primary ExaminerMartin P. Schwadron Assistant Examiner-A. M. Zupcic Attorney-R0bb & Robb [57] ABSTRACT The disclosure hereof is of an hydraulic power amplifier or intensifier which includes a drive unit and a driven unit formed of large and small piston elements respectively, interconnected so as to be simultaneously operable, pressure applied to the larger of the units being calculated to in turn produce at the output end of the driven unit large pressures for operating various types of devices such as those used in utility construction and maintenance including cutters, swagers and the like, the disclosure providing a portable unit incorporating various controls which are desirable in the elements under consideration, and particularly making provision for pre-charging the system which produces the high pressure and applies the same to the operating tools. Control of the intensifier is effected by hand manipulation remotely arranged and connected so as to avail of low pressure for activating higher pressure elements or instrumentalities, the pre-charging arrangement serving to maintain the system at full pressure without air pockets and likewise acting to grip or hold parts initially prior to ultimate manipulation by the pressures supplied.

5 Claims, 7 Drawing Figures Emma States Patent 1 [111 3,748,860

Castleberry July 31, 1973 PAIENIEUJULQ 1 I975 SHEEF 2 (IF 3 INVENTOR. J. C. Cosfleberry BY 7 m lw Fla?) HYDRAULIC BOOSTER OBJECTS OF THE INVENTION It is a primary object of this invention to provide a portable hydraulic power intensifier which is of simple construction, availing of large and small piston and cylinder elements which are drive and driven units respectively so that power impressed upon the larger unit will in turn be intensified on the order of ten times at the smaller unit, to make available at the output end of the smaller unit pressures in the order of ten thousand pounds per square inch which are very useful to operate tools for cutting cables, swaging the same and other operations which can avail of such pressures.

A further object of the invention is to provide a novel arrangement such that the maintenance of a precharged system at all times is achieved, pre-charging being effected by maintaining the system pressures and yet arranged in such a manner that the pre-charging action is terminated practically instantaneously with the development of high pressure which is the ultimate object of the mechanism.

A further object of the invention is to provide a novel arrangement of parts which will facilitate the manipulation of such devices as are used in utility construction, by the provision of hand held controls which by remote application of power can efi'ect actuation of the intensifier to develop the pressure desired and likewise provide for return of the system to its initial inactive status so to speak, preliminarily to effecting additional operations thereby.

A still further object of the invention is to arrange the various parts of the intensifier so that work performing devices are actuated thereby from the high pressure end of the device and the power developed can be initially derived from relatively lower power under the control of suitable valve arrangements and by remote control of hand-held and manually manipulated means or instrumentalities.

Further and more particular objects of the invention will be understood from a consideration of the specifi cation appended hereto and disclosed in the drawings wherein:

FIG.- 1 is a perspective view of the major portion of the intensifier of this invention from one aspect.

FIG. 2 is a similar but fragmentary view of the intensifier shown in FIG. 1 from the opposite side.

FIG. 3 is a vertical view partly in section disclosing certain of the major components of the intensifier without piping or other valves associated therewith.

FIG. 4 is a side view partly in section, showing the control valve used for the intensifier.

FIG. 5 is an end view of the valve of FIG. 4.

FIG. 6 is a schematic diagram of the hydraulic system used in this invention.

FIG. 7 is a view on a greatly reduced scale illustrating the general relationship of the parts in a complete system in accordance with this invention.

DESCRIPTION OF THE INVENTION Referring to FIGS. 1, 2 and 7 preliminarily, the intensifier or amplifier of this invention is shown as comprising a power unit generally indicated at l, a control unit 2 and a work performing device generally designated 3.

The power unit 1 in turn comprises a drive unit designated 4 generally as indicated in FIG. 3, and a driven unit 5, these both comprising hydraulic piston and cylinder elements wherein, as indicated in FIG. 3, the first cylinder and piston element includes a cylinder section 6 and a piston 7 operable therewithin.

The driven unit 5 likewise includes hydrauliccylinder 8 and piston 9 operable therein, the piston 9 being of substantially less diameter than the piston 7 and in fact arranged to provide for power multiplication in the order of ten times the input.

Since it will be clear that this intensifier or amplifier as it may be designated is an hydraulic arrangement, certain hydraulic connections, valves and controls are necessary and will therefore be described as associated with the respective parts heretofore set forth.

With the foregoing in mind, therefore, it will be seen that the piston 7 operating within the cylinder 6 is connected to the piston 9; in fact the piston 9 comprising a hollow tubular body 10 fastened at its lower end to the piston 7 and at its upper end being provided with a closure to define the piston 9, suitable seals being furnished in accordance with desired hydraulic practice, fluid flow from an hydraulic power source being admitted at the inlet 11 at the lower end of the cylinder 6 as more clearly shown in the piping diagram of FIG. 6, schematically and for illustrative purposes as will be readily understood.

The piston 7 is provided with a seal at 12 operating in the cylinder 6 to prevent escape of fluid between the cylinder and piston, suitable seals for the piston 9 being indicated at 12a.

For additional descriptive purposes, the piping diagram of FIG. 6 will be referred to from this point, in order to illustrate with greater particularity the relationship of certain of the parts, some of which are conventional and thus not described in detail.

Turning therefore to a consideration of FIG. 6, hydraulic pressure is supplied to this intensifier from a source indicated at 13, connected or coupled to a coupling at 14 indicated in FIG. 1 in the upper left-hand portion of the same, this pressure being often on the order of 2,000 lbs. per square inch, and being directed to a pressure reducing valve generally designated 15 shown in FIG. 2, the same being of conventional form and therefore not more particularly described, it being sufficient to state that the pressure is introduced thereinto as indicated, with the valve 15 arranged to provide about 1,000 lbs. per square inch of fluid under pressure at any outlet therefrom, this pressure regulating valve maintaining such pressure at relatively constant value, this being what will be termed a relatively low pressure supply from this point on, and sometimes stated as being the system pressure.

Suitably connected with the pressure reducing valve 15 is a check valve 16, set to open for the purposes hereof at about 65 lbs. per square inch.

The system pressure passing through the check valve 16 enters a line 17 and passes from there to a four-way three-position tandem center valve 18.

The pressure directed to the four-way valve 18 is in turn, upon actuation of means which will be subsequently described, directed to the line 19 through suitable fittings engaged therewith and not described in detail, and in turn the line 19 is connected to the inlet 11 previously mentioned.

This inlet 1 l delivers the system pressure or relatively low fluid pressure referred to, through the line 19 beneath the piston 7, and thereby moving the piston upwardly upon manipulation of control means which will be described subsequently.

It will also be noted, and an important aspect of the invention is described at this point, as residing in the additional connection of the line 19 with a further line 20 directed to an opening 21 in the wall of the cylinder 8 at the lower end thereof just above the piston 9 as shown in FIG. 3 and in FIG. 6 diagrammatically.

It will thus be understood that the system pressure directed through the line 19 to move the piston 7, will likewise be directed to the cylinder 8, to thereby precharge the high pressure section of the intensifier so that any air pockets or non-fluid spaces therein will be completely filled with fluid and the system pressure imposed on the high pressure or driven unit initially when pressure is directed to the system.

The high pressure fluid supply or output source which is thereby provided by the cylinder 8 may be in turn directed through an output line 22 from the outlet 23 of said cylinder 8 to a control valve indicated in FIG. 7 at 24.

From the control valve 24, the high pressure line 25 leads to a work performing device generally designated 3 previously mentioned and of conventional form such as an hydraulic punch, not further described, but wellknown in the art.

In order to provide for return of fluid to the source from the four-way valve 18, a suitable line such as 26 is availed of, and connected to the pressure reducing valve previously mentioned, a suitable fitting being provided to make necessary connections and including the coupling 27 at the end thereof as indicated in FIGS. 1 and 2 all the lines not being shown in said Figures as will be readily understood.

Since the four-way valve 18 is pilot operated, the manner of effecting such operation will now be described as being controlled by the control valve 24 more particularly disclosed in FIG. 4 as including a generally rectilinear body 28, this unit being specifically described as comprising two two-position, threeway sections therein, and since both halves of the device are identical, only one will be referred to as illustrated in section therein, the same comprising a pushbutton 29 for operating a spool 30 normally maintained in its uppermost closed position by a spring 31.

A pressure line 32 leads from reducing valve 15, which regulates pressure to about 1,000 lbs. per square inch, to a port 32a in a manifold 36 mounted at the upper end of the intensifier as shown in FIGS. 1 and 2.

From a port connected to the port 32a previously referred to, a pressure line 35 in turn extends to a port 33 in the control valve 24.

When the button 29 is depressed, and spool 30 correspondingly, fluid introduced through port 33 will be directed to port 34 in the control valve 24, and from said port to a line 38 which returns to the manifold 36 at a port 32b therein.

A line 39 extending from the manifold 36, receives the fluid directed through the port 32b and said fluid thence flows through said line to the pilot end 40 of the four-way valve 18.

Pilot pressure thereby directed to the four-way valve 18 will move a spool therein to permit the system pressure imposed on the line 17 to be directed to the line 19 and thence through the opening 11 in the cylinder 6 below the piston 7, causing the said piston to rise upwardly.

The upward movement of the piston as described will result incorresponding movement of the piston 9 within the cylinder 8, and as said piston 9 rises it will shut the port or opening 21 in the cylinder 8, thereby preventing any high pressure developed within the cylinder 8 from passing back through the line 26.

The pressure in cylinder 8 developed as stated, will thereupon be imposed at the outlet 23 upon the line 22, and since this line passes through the control valve through port 41 therein, it may thereupon be directed through line 25 to the working performing device 3 to cause the same to be operated in accordance with desired practice.

Assuming that the work by the device 3 has been performed, it will be desirable to again return the piston 7 to its initial starting position so that it will again drive the piston 9 upwardly for subsequent work, and to that end the parallel control member 42 of the control valve 24 may be operated to direct fluid from the port 33 to the outlet port 44 in the said valve 24, this pressure in turn passing to the line 45 back through the manifold and port 46 therein to a further line 47 so as to in turn reach the end 48 of the four-way valve 18.

This pressure directed through the end 48 of the four-way valve, will cause the spool therewithin to move so as to direct pressure to a line 49 extending from said valve to a suitable opening 50, at the upper end of the cylinder 6, and thereby above the piston 7, so as to move the said piston downwardly within the said cylinder, this line 49 having a connection such as suggested at 51, and more particularly disclosed in FIG. 1, to provide for a double acting operation of tools such as the work performing device 3 where necessary.

There are suitable return lines from the four-way valve for example, such as that designated 26 back to a tank 52 and an additional return line 53 from the valve 24 through the manifold 36 and to a line 54 leading therefrom to the reducing valve 15 and thence to the tank 52 through line 54a.

It will therefore be seen that the hydraulic valve unit 4 will in turn derive the driven unit 5 to produce ten times the pressure therewithin as is required to operate the unit 4 and this in turn will be directed through the control valve 24 and under its control to a work performing device 3 or similar device similarly connected.

Thus intensification of the fluid pressure is accomplished and controlled within a relatively small package, it being contemplated that the control valve 24 may be handled at some distance from the intensifier unit itself, so that at the place of performing the work by the work performing device 3, the valve may be readily manipulated to carry out the functions heretofore described.

It should be understood that by reason of the connection of the system pressure through the line 20 with the opening 21 in the side of the cylinder 8, that system pressure exists at all times as long as there is any fluid pressure in the lines leading to the four-way valve and from the four-way valve, to the work performing device with the respective parts in the positions shown.

This will tend to maintain the work performing device in what may be termed a closed position, this in effect enabling a piece of work to be held within the work performing device without actually performing any work thereon, this being the case where the four-way valve has been actuated sufficiently to admit some fluid to the line 20 and thence to impose the system pressure in the high pressure end of the driven unit S.

It is only necessary to manipulate the control members 29 and 42 to determine the position of the element of the work performing device 3, and at all times the system is pre-charged, the pre-charge is cut off automatically when pressure stroke is started in the first cylinder and piston unit and imposed upon the second piston and cylinder or high pressure unit.

A suitable filter may be provided in the system, and the precharging action will cause the hydraculic fluid to pass through the same at each cycle to remove dirt and impurities, thereby adding to the life of parts which would be adversely affected thereby.

I claim:

1. In a closed system hydraulic power amplifier connected to a work performing device of the class described, in combination, an hydraulic drive unit supplied from a low pressure fluid supply, a driven hydraulic unit mechanically connected to and operable by the drive unit to produce a high pressure fluid supply output source and in turn arranged to direct said high pressure fluid output source to operate the work performing device, and means to precharge said high pressure fluid output source with additional fluid to assure complete fill with fluid comprising connections to direct fluid from said low pressure fluid supply to said high pressure fluid output source and means including valving means to supply said low pressure fluid to said high pressure fluid output source selectively only during a pre-determined intial period during actuation of said drive unit.

'2. The combination as claimed in claim 1, wherein the drive unit comprises a first cylinder and piston operable therein, and the driven unit includes a second smaller cylinder with piston operable therein, simultaneously with the first piston.

3. The combination as claimed in claim 2, wherein the low pressure fluid supply to the second cylinder is directed thereinto through an opening in the side wall thereof, and is shut off when the second piston passes over said opening.

4. The combination as claimed in claim 2, wherein the first piston is arranged to move axially from a first position to a second position and return in the first cylinder, the second piston is an elongated member extending axially from the first piston, the second cylinder surrounding the second piston, said second cylinder having an opening in the wall at the one end thereof, which is open when the second piston is at its first position, and is closed by said piston when it has moved axially a pre-determined distance therefrom, whereby low pressure fluid from said source thereof is supplied to said second cylinder until said piston closes said opening.

5. The combination as claimed in claim 1, wherein remote control instrumentalities are connected to the source of fluid pressue and the valve means, said instrumentalities including control members operable manually to direct pilot pressure to the valve means and shift elements therein to determine the application of the said fluid pressure to the drive unit, and thus the direction of the movement thereof and of the driven unit likewise. 

1. In a closed system hydraulic power amplifier connected to a work performing device of the class described, in combination, an hydraulic drive unit supplied from a low pressure fluid supply, a driven hydraulic unit mechanically connected to and operable by the drive unit to produce a high pressure fluid supply output source and in turn arranged to direct said high pressure fluid output source to operate the work performing device, and means to precharge said high pressure fluid output source with additional fluid to assure complete fill with fluid comprising connections to direct fluid from said low pressure fluid supply to said high pressure fluid output source and means including valving means to supply said low pressure fluid to said high pressure fluid output source selectively only during a pre-determined intial period during actuation of said drive unit.
 2. The combination as claimed in claim 1, wherein the drive unit comprises a first cylinder and piston operable therein, and the driven unit includes a second smaller cylinder with piston operable therein, simultaneously with the first piston.
 3. The combination as claimed in claim 2, wherein the low pressure fluid supply to the second cylinder is directed thereinto through an opening in the side wall thereof, and is shut off when the second piston passes over said opening.
 4. The combination as claimed in claim 2, wherein the first piston is arranged to move axially from a first position to a second position and return in the first cylinder, the second piston is an elongated member extending axially from the first piston, the second cylinder surrounding the second piston, said second cylinder having an opening in the wall at the one end thereof, which is open when the second piston is at its first position, and is closed by said piston when it has moved axially a pre-determined distance therefrom, whereby low pressure fluid from said source thereof is supplied to said second cylinder until said piston closes said opening.
 5. The combination as claimed in claim 1, wherein remote control instrumentalities are connected to the source of fluid pressue and the valve means, said instrumentalities including control members operable manually to direct pilot pressure to the valve means and shift elements therein to determine the application of the said fluid pressure to the drive unit, and thus the direction of the movement thereof and of the driven unit likewise. 